Telescopic structure



l TELESCOPIC `STRUCTURE Fiied June 16, 1945 IN V EN TOR.

f5 ATTORNEYS G. o. BENSON 2,483,396

fr# JQ/Q Patented Oct. 4, 1949 UNITED STATES rATENT OFFICE TELESCOPICSTRUCTURE Application June 16, 1945, Serial No. 599,925

4 Claims.

This invention relates to a, telescopic structure and more particularlyto such a structure, such as a portable radio antenna, composed oftelescoping sections which are nested together and which can be rapidlyextended to provide a mast capable of being set upon any mobile orstationary support and used for sending or receiving radio messages.However, the invention is not confined to any particular use and canalso be used as a telescopic support for signal lights and for otherlike uses, such as tent poles.

One of the principal objects of the present invention is to provide sucha telescopic structure in which the sections can be quickly extended andquickly collapsed and in which the structure is securely held in itsextended position with little danger of accidental release.

Another object is to provide such a telescopic structure which, whenextended, is strong and will adequately resist axial, torsional andbending strains.

Another object is to provide such a telescoping joint including a. crosspin in which the cross pin can be located so as to impair the strengthof the telescopic joint to the least degree.

Another object is to provide a telescopic structure which does notrequire tools to extend or collapse the several sections.

Another aim is to provide such a telescopic structure which is simpleand inexpensive in construction and can be repeatedly extended andnested without objectionable wear or deterioration.

Other objects and advantages will appear from the following descriptionand drawings in which:

Fig. 1 is a fragmentary longitudinal section, partly in elevation, ofseveral sections of a telescopic mast embodying my invention.

Figs. 2-8 represent an exploded perspective view of the several partsillustrated in Fig. 1.

Figs. 9 and 10 are transverse sections taken on the correspondinglynumbered lines on Fig. 1.

Fig. 11 is a fragmentary view similar to Fig. l and showing a, modifiedform of the invention.

Fig. 12 is a fragmentary view similar to Figs. l and 11 and showinganother form of the invention.

Fig. 13 is a transverse section taken on line I3-I3, Fig. 12.

While the invention is not conned to any particular use, it is shown asembodied in a metal antenna mast which has a tubular metal base orenclosing section I5, a next succeeding section I5a and any number ofsucceeding sections I5b, all of which sections are `of progressivelysmaller diamw other suitable manner.

eter so as to telescope into one another and into the base section I5 sothat in the nested condition of the parts the entire mast is containedwithin the base section I5. Except as to the necessary diierences indiameter, the sections I5, I5a and I5?) are generally similar inconstruction and hence the same reference numerals have been applied tothose parts which are identical except as to size.

The outer end of each section I5, I5a, I5b` is shown as being beveled,as indicated at I6, this not being necessary, however, and as beingexternally threaded, as indicated at I8, to receive a threaded retainingring I9, each of these retaining rings I9 having an inwardly projectingannular flange 2li which'is beveled to fit the bevel I6 and also has abore 2| tting the periphery of the next succeeding smaller section.

Each of the sections I5a and I5b is provided at its opposite end with across pin 23, the base section I5 being unprovided with such a pininasmuch as it is the larger terminal section of the mast. These pinsextend diametrically through the sections I5a, I5b at a substantialdistance from the adjacent inner ends thereof and the opposite ends ofeach pin project outwardly from the periphery of its section I5a |517 adistance approximately equal to the space between its section and thenext succeeding larger section.

Except for the smallest or tip section, each of the sections is providedat its outer end with means engaging and supporting the pin 23 of thenext succeeding smaller section so as to hold the mast in an extendedcondition. With each of the sections I5a, I5b these means comprise apair of semi-cylindrical plates 24 which are fitted in the outer end ofeach of the sections in opposed relation to each other and can besecured to the section by welding, riveting, brazing or in any Each pairof these plates 24 have their longitudinal opposing edges spaced fromeach other to provide a pair of opposite Ways or grooves 25 which are ofa width to receive the projecting ends of the pin 23 of the nextsucceeding smaller section and thereby permit this pin to pass theplates 24. The plates are also positioned at a distance from the outerend of the corresponding section I5a, I5bI so as to provide acircumferentially extending annular way 26 between the ends of each pairof plates 24 and the adjacent retaining ring I9, these circumferentialways 26 likewise being of a width to receive the projecting ends of thepin 23 of the next succeeding smaller section. At its outer Vend each ofthe plates 24 is provided with an axially extending notch 28 which isshaped to receive the corresponding end of the companion pin 23. Thesenotches may be of any desired shape or depth and are preferably locatedat the centers of the plates 24 so that the companion notches arediametrically opposite each other to receive the opposite ends of thecompanion pin 23.

The base section YI5 is provided at its outer end with a pair ofsemi-cylindrical plates 30 which are generally similar to the plates 24except that they are formed to support the pin 23 ofthe succeedingsection I5a at different-elevations thereby to permit of adjusting theheight of the mast. Thus, these semi-cylindrical.platesi are securedwithin the upperendof lthe-baselsection I l5 in any suitable mannerandwith'their'longitudinal edges in opposed spacedfrelationto :each otherto provide opposite axially extending ways 3| for the projecting ends ofthe pin 23 'ofthe section la. 'J from the outer. end or the sectionrlutoiprovide .La circumferential wayfor the projecting ends .zof Athispin and. each plate. isprovide'din itsouter ,endiedgewith. a notch'lsirnler to thepnotches E28A of the platesLZ'lland-arrangedldiametrically1r.;

opposite;..each.` otherV .to 4.receivejzandf retainjzthe f oppositeprojecting ends .of ...theL pin.;23 :ofi vthe -;sectiorrd5a.xHoweyergieachplate;38 .is provided along one of its edges with aplurality. nf. bayonet f slots 34; ofsufficient width. tof receive:theocr-vl respondingend of the pin' 231er thesectioni-la, '.each;A of.these; bayonet slots 34 being: oppositef a companion Abayonet slot .'34for'V the companion plate. 30 so that ealclrzpairnf.thetbayonetislotsi.' 34, `on :the pair voli; plates' 3!r can. receiveV and, -re-4 isterwith theaxially extending.aways.2251:pro-` videdbeween theopposing.edges of these plates 2.4,wl'iereupon.:the section being withdrawncanche withdrawn further, the-projectingends of its .-pin.;23 travelingalong the-.ways- 25.until they Fstrike thezinwardlyl projectingrlangeLZlln of'. the corresponding screw ring i9. -Vhennthispccursthe sections can-be` rotated relative te'eachother, athemrojectingends-of. the pinof V.thesection .being-withdrawn traveling'in .thecircumferen- :tial way ESbetween this screw ring. and-thelfadzjacentgplates 24. This rotationofnthe Isections r-.relative-toleachother is continueduntil theapro- `jecting ends of thepin '23 nd the`diam-etrically :opposite notches'ZB .in the plates ZA-into which theydrop so as rtofrestrainthefsectionsagainst 1 further rotation -relativetto 'Y each fothenandzato hold the two ysections in their-extendedposition. .In-withdrawing the section 15a from thebase section I5= anadjustmentor thelengthof-the 4Inast lcan-be eiected. -Thus, inwithdrawing the projecting ends of the pin.23 of the section '15a :alongthe ways tanyrone of .the seriesopairs of bayonet slots can ybeselectedv and thesections .I5-andl5wturned relative to-one another whenthe projecting ends of-this .pin come into -registerwith the. selectedpair Vof :bayonet slots A'3l. Upon then turning the sections 155, .ldrel- ...ative to each-other. the projecting-ends` of vthe :spin: 23 ofthesectionA lctrwill be rvcaughtandretainedl inthe depending part .of,the fbayonet Also these plates Si) are spaced g 4 slot. It will be seenthat the length of the mast will depend upon which of the pairs ofbayonet slots 311 is selected and that the maximum length is obtained bymoving the pin 23 of the section its the full length of the way 3i andthen turning the sections to cause the projecting ends of this pin totraverse the circumferential way 32 until they seatlthemselves in thenotches 33.

Asquires a reversal of the above procedure.

It will also be seenv that nesting the sections 15a and ib in the basesection i5 merely re- Thus,

A.totelescope any of the sections i517 into the next larger section 15bor |5a, the smaller section is `dravvn: axially Youtward to free theprojecting ends .uofits pin I23ifrornI the pair of notches 23 in which.theyeweref-seated whereupon the sections can be. r,otated-..with. theprojecting ends of this pin traversing the 'circumferential way 2*?between lthe'corresponding plates 2li and screw ring I9.

When the projecting vends of this pin 23 come of the-sectionnia canbe-"freedffromsthewend notches y35 of thesection l5in.afsimilarimanner.

`moved axially and then ,rotated so as to :ireethe projectingendsof-thisfV pin `from-the V...pair-.fof bayonet slots 34 and place .them.in the/.ways '3| in which position the-sections: l5-.and:f1-5a=are.free to be telescoped.

.another section all that `is-necessary risatoY un- Vscrew the.corresponding screw ring i9. :The

- smaller--sectionacani.then be .withdrawn-.com-

pletely from the largersection,^:thmprojecting ends offits pin23j-passing throughnthe` ax-ialiway 25 betwe'enthe plates. 24; of `:the.larger fsection.

It will --be 'seen thatzthe formpfthe-ways provided between thesemi-cylindrical platesand the arrangement of the bayonet slotsto\1eceive and retain thevprojeoting vcndssofthe'nextsucceeolingr`snialleritubular .section :candice .Waried f in many ways'tosuit-theparticulanmanipulation desired to set `Llp-andlnestftheffmast.

Thus, int Fig.. l1 one of the @tubular- 'sections 38 of the telescopicstructure-isshown as -having a pairiof semi-cylindrical plates 3.946.1itted and riveted in its .router end; these, plates being .similarto the -pla-tes- '24 and.Y 3B ot1 the form of-` the invention shown rinFigs. :fle-10. ..As--with\.the form of the invention shown in Figs.11G,\.\the opposing edges of. the. semi-cylindrical plates are 1 spaced.from; each otheruto. fprovide waysl. `for the, projecting ends .of :thecross 1pin 46 at" the inner end of the next succeeding-smaller-section(not shown). fHoweveig linzthefformipf Athetinvention shownin Fig.. 11icacher-these ways 4l has a relativelywide-entrance-portion-LQZ .leadingtoa circumferential continuation #i3 oizthis-vway.

.At the end of this circumferential.continuation -43 a notch 44 isprovidedin,-the^-plate di! so that the circumferential continuation.ltfzand. notch .w44 jointly form a bayonet slot :for receiving-i` and 5and 13, one of the -tubularsections 48 is shown as having a pair ofsemi-cylindrical plates 49, 50 itted and riveted in its outer end, theseplates being similar to the plates 24 and 30 of the form of theinvention shown in Figs. 1-10. As with the form of the invention shownin Figs. 1-10, the opposing edges of each pair of semi-,cylindricalplates are spaced from each other to provide a way 5l for the projectingends of the cross pin at the inner end of the nextsucceeding vsmallersection (not shown). Also thediametrically opposite edges of theseplates 49 and 50 are shown as provided with a-series of pairs of bayonetslots 52 along these ways 5|, these bayonet slots functioning in thesame manner as the bayonet slots and the bayonet slots 52 also are inthe form of a series of steps so that the projecting ends of the crosspin pass from one bayonet slot to the other in collapsing the structure.The difference in manipulating the form of the invention shown in Figs.12 and 18 is believed to be readily apparl ent.

The essential difference between the form of the invention shown inFigs. 1-10 and the forms of the invention shown in Figs. 11 and 12 isthat in the form of the invention shown in Figs. 1-10 the pins 23, inthe extended position of the mast, are arranged at the outer ends of thelaps between the 'sections |5a and |512 since they rest in the notches28 provided at the outer extremities of the plates 24. In the forms ofthe invention shown in Figs. 11 and 12 the pins are arranged close tothe inner extremity of each section 38, 48 and in the extended positionof the mast are located a Substantial distance from the outer extremityof the lap between each pair of sections. As a result the holes for thepins, in the form of the invention shown in Figs. 1-10, are drilled nearthe zone of greatest strain b..- tween the mast sections, this being, ofcourse, at the outer extremities of the laps, and hence the simplicityof the form of the invention shown in Figs. 1-10 is achieved at somesacrce to the strength of the mast due to the weakening resulting fromdrilling for the holes of the pins 23 near the zone of greatest strain.Conversely, while the constructions shown in Figs. 11 and l2 are morecomplicated, the drilling of the holes for the pins is near the innerextremity of each section and at the inner extremities of the lapsbetween the sections so that the mast is Weakened to the least degree bysuch drilling.

From the foregoing it will be seen that the pairs of semi-cylindricalplates lsecured in the outer end of the tubular telescopic sections andspaced to provide ways and notched to provide retaining recesses for theprojecting ends of a cross pin for the next smaller tubular telescopicsection provide a simple, inexpensive and extremely sturdy joint forreleasably holding the sections extended and at the same time permittingthem to be nested by a simple manipulation of the sections.

I claim as my invention:

l. A telescopic structure, comprising inner and outer slidably androtatably interfitted cylindrical tubes, the inside diameter of saidouter tube being substantially larger than the outside diameter of saidinner tube to form an annular chamber therebetween, a pair of membersprojecting laterally outwardly from one end of said inner tube Cil Cil

A`and from oppositesides thereof: into said chamber, and a pairof'semi-cylindricalplates within said chamber conforming tothe bore ofsaid outer outer slidably and rotatably interitted cylindrical tubes,the inside diameter of said outer tube being substantially larger thanthe outside diameter of lsaid inner tube to form an annular chambertherebetween, a pair of members projecting laterally outwardly from oneend of said inner tube and from opposite sides thereof into saidchamber, a pair of semi-cylindrical plates within said chamberconforming to the bore of said outer tube, means securing said plates toopposite sides of said bore, said plates having axially extending edgesspaced to provide a pair of axially extending ways of sulicient width toreceive said members of said inner tube, lsaid plates fitting theperiphery of said inner tube, each of said plates having along one oiits edges defining a correspending one oi said ways a bayonet slotadapted to receive a corresponding one of said members and releasablysupport said inner tube in an extended position.

3. A telescopic structure, comprising inner and outer slidably androtatably intertted cylindrical tubes, the inside diameter of said outertube being substantially larger than the outside diameter of said innertube to form an annular chamber therebetween, a flange projectinginwardly from one end of said outer tube and engaging the periphery ofsaid inner tube to close the corresponding end of said chamber, a pairof members projecting laterally outwardly from one end of said innertube and from opposite sides thereof into said chamber, a pair ofsemi-cylindrical plates within said chamber conforming to the bore ofsaid outer tube, means securing said plates to opposite sides of saidbore, said plates having axially extending edges spaced to provide apair of axially extending ways of sucient width to receive said membersof said inner tube, said plates tting the periphery of said inner tubeand being spaced from said ange to provide a circumferential way ofsuiiicient width to receive said members, said plates each having alongits circumferential edge adjacent said ange of said outer tube a notchadapted to receive the corresponding one of said members and releasablysupport said inner tube in an extended position, and each of said platesalso being each provided along one of its edges dening a correspondingone of said ways with a series of spaced bayonet slots each adapted toreceive a corresponding one of said members and releasably support saidinner tube in a corresponding extended position.

fl. A telescopic structure, comprising inner and outer slidably androtatably intertted cylindrical tubes, the inside diameter of said outertube being substantially larger than the outside diameter of said innertube to form an annular chamber therebetween, an annular flangeprojecting inwardly from one end of said outer tube and engaging theperiphery of said inner tube to close the corresponding end of saidchamber, a pair of members projecting laterally outwardly from the 75opposite end of said inner tube and from opposite

